Search Results (533)

Replication-competent virus particles hold significant therapeutic potential in application as oncolytic viruses or cancer vaccines. Ensuring the viral integrity of these particles is crucial for their infectivity, safety, and efficacy. Enveloped virus particles, in particular, offer large gene insert capacities and customizable target specificity. However, their sensitivity to environmental factors presents challenges in bioprocessing, potentially compromising high quality standards and cost-effective production. This review provides an in-depth analysis of the purification process steps for replication-competent enveloped virus particles, emphasizing the importance of maintaining viral integrity. It evaluates bioprocessing methods from cell culture harvest to final sterile filtration, including centrifugation, chromatographic, and filtration purification techniques. Furthermore, the manuscript delves into formulation and storage strategies necessary to preserve the functional and structural integrity of virus particles, ensuring their long-term stability and therapeutic efficacy. To assess the impact of process steps on particles and determine their quality and integrity, advanced analytical methods are required. This review evaluates commonly used methods for assessing viral integrity, such as infectious titer assays, total virus particle quantification, and structural analysis. By providing a comprehensive overview of the current state of bioprocessing for replication-competent enveloped virus particles, this review aims to guide researchers and industry professionals in developing robust and efficient purification processes. The insights gained from this analysis will contribute to the advancement of virus-based therapeutics, ultimately supporting the development of safe, effective, and economically viable treatments for various diseases. Full article

The systemic treatment of breast cancer has evolved remarkably over the past decades. With the introduction of immune checkpoint inhibitors (ICIs), clinical outcomes for solid tumor malignancies have significantly improved. However, in breast cancer, the indication for ICIs is currently limited to triple-negative breast cancer (TNBC) only. In high-risk luminal B hormone receptor-positive (HR+) breast cancer (BC) and HER2-positive (HER2+) BC, modest efficacy of ICI and chemotherapy combinations were identified in the neoadjuvant setting. To address the unmet need, several novel immunotherapy strategies are being tested in ongoing clinical trials as summarized in the current review: bispecific antibodies, chimeric antigen receptor T-cell therapy (CAR-T), T-cell receptors (TCRs), tumor-infiltrating lymphocytes (TILs), tumor vaccines, and oncolytic virus therapy. Full article

Oncolytic herpes simplex virus (oHSV) represents a promising therapeutic approach to treating cancers by virtue of its selective replication in and lysis of tumor cells, with stimulation of host antitumor immunity. At present, four OV drugs have been approved for the treatment of cancers worldwide, two of which are oHSV drugs that have received extensive attention, known as T-VEC and Delytact. This review discusses the history, mechanism of action, clinical development, quality control, and evaluation principles of oHSV products, including viral species and genetic modifications that have improved these products’ therapeutic potential, limitations, and future directions. Integration of oHSVs with immunotherapeutic agents and conventional therapies has a promising future in the field of treatment of malignant tumors. Although much progress has been achieved, there is still much work to be done regarding the optimization of treatment protocols and the quality control of oncolytic virus drugs. The approval of various oncolytic virus therapies underlines their clinical relevance, safety, and efficacy, thereby paving the way for further research aimed at overcoming the existing limitations and enhancing patient responses. Full article

The insertion of a transgene downstream of the L3-23K or L5-Fiber region was reported as a vital strategy for arming E3 non-deleted oncolytic adenoviruses. However, depending on the percentage of codons with G/C at the third base position (GC3%) and the type of splicing acceptor, an insert downstream of the L5-Fiber region may substantially affect virus fitness. Since the insertion of transgenes downstream of the L3-23K and L5-Fiber regions has never been compared in terms of their expression levels and impact on virus fitness, we assessed the total virus yield, cytolytic efficacy, and plaque size of Ad5-delta-24-RGD (Ad5Δ24RGD) armed with EGFP, FLuc, the suppressor of RNA silencing p19, soluble wild-type human/mouse and high-affinity human programmed cell death receptor-1 (PD-1/PDCD1) ectodomains, and soluble human hyaluronidase PH20/SPAM1. The insertion of transgenes downstream of the L3-23K region ensures their production at considerably higher levels. However, the insertion of transgenes downstream of either region differentially and unpredictably affects the oncolytic potency of Ad5Δ24RGD, which cannot be explained by GC3% or expression level alone. Surprisingly, the expression of the human and mouse PD-1 ectodomains with 83.1% and 70.1% GC3%, respectively, does not affect cytolytic efficacy but increases the plaque size in a cell line-dependent manner. Full article

Cancer gene therapy is attracting considerable attention as a new treatment method for overcoming intractable cancers. CAR-T cell therapy has already achieved remarkable results, particularly for hematological tumors. Because CAR-T cells can increase within the body, they have the advantage of requiring only a single administration. In addition, CAR-T cell therapy targeting the CD19 antigen has been established for relapsed or refractory disease in young people with CD19-positive acute B-cell leukemia (B-acute lymphoblastic leukemia, B-ALL) and diffuse large B-cell lymphoma (DLBCL). In addition to CAR-T cell therapy, oncolytic viruses represent a promising approach for cancer treatment, with some already in clinical use and others being researched for their potential benefits. These viruses infect and kill cancer cells, triggering an immune response that helps the body recognize and fight cancer. Oncolytic virus therapy is a form of immunotherapy that uses modified viruses to target and destroy tumor cells while potentially stimulating antitumor immune responses. These viruses have shown promising activity in clinical trials, with some approved for specific cancers like melanoma. Research is ongoing to improve their efficacy, expand their use to other cancer types, and overcome the logistical challenges associated with their delivery. Gene therapy can potentially treat diseases caused by recessive gene disorders like cystic fibrosis, hemophilia, muscular dystrophy, and sickle cell anemia, as well as acquired genetic diseases, such as cancer and viral infections like acquired immunodeficiency syndrome (AIDS). Full article

Objectives: Pancreatic cancer remains a therapeutic challenge due to its immunosuppressive microenvironment and treatment resistance. This study aimed to develop a novel recombinant oncolytic vaccinia virus (VVL-GL7) co-expressing granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin-7 (IL-7), designed to enhance anti-tumor immunity and synergize with immune checkpoint inhibitors. Methods: VVL-GL7 was constructed through CRISPR/Cas9-mediated knockout of TK and A49 genes, combined with the simultaneous insertion of dual cytokine-encoding cassettes. Anti-tumor efficacy was evaluated in vitro and in vivo using C57BL/6 mouse and Syrian hamster pancreatic cancer models. Comprehensive immune profiling evaluated CD8⁺ T-cell and macrophage infiltration dynamics while simultaneously assessing memory T-cell differentiation patterns using flow cytometry. Preclinical combination studies of VVL-GL7 and the PD-1 immune checkpoint inhibitor were systematically evaluated in a syngeneic pancreatic cancer model. Results: VVL-GL7 exhibited potent oncolytic activity, inducing significant tumor regression in both preclinical models. VVL-GL7 therapy significantly augmented CD8⁺ T-cell and macrophage infiltration within the tumor microenvironment, while concomitantly driving memory T-cell differentiation. The synergistic effects of VVL-GL7 and the PD-1 blockade further improved therapeutic outcomes, resulting in significantly higher tumor remission rates compared to monotherapy and achieving complete tumor regression in pancreatic cancer models. Conclusions: VVL-GL7 reprograms the immunosuppressive tumor microenvironment and synergizes with anti-PD-1 antibodies to overcome resistance in pancreatic cancer. Full article

Parvoviruses are small, single-stranded DNA viruses that have evolved sophisticated mechanisms to hijack host cell machinery for replication and persistence. One critical aspect of this interaction involves the manipulation of the host’s DNA Damage Response (DDR) pathways. While the viral genome is comparatively simple, parvoviruses have developed strategies that cause significant DNA damage, activate DDR pathways, and disrupt the host cell cycle. This review will explore the impact of parvovirus infections on host genome stability, focusing on key viral species such as Adeno-Associated Virus (AAV), Minute Virus of Mice (MVM), and Human Bocavirus (HBoV), and their interactions with DDR proteins. Since parvoviruses are used as oncolytic agents and gene therapy vectors, a better understanding of cellular DDR pathways will aid in engineering potent anti-cancer agents and gene therapies for chronic diseases. Full article

Background: The heterogeneity of sarcomas and resulting distinct sub-type specific characteristics, their high recurrence rates, and tendency for distant metastasis, continue to present significant challenges to providing optimal treatments. Objective: To provide a comprehensive review of current literature and clinical trials in gene and cell therapies for sarcomas. Methods: A comprehensive literature search was conducted utilizing the following databases: PubMed, Medline, Google Scholar and clinicaltrials.gov. Search terms included “gene therapy”, “cell therapy”, “NK cell therapy, “CAR-T therapy”, “virotherapy”, “sarcoma”, “gene therapy”, and “solid tumors”. Additional sources were identified through manual searching for references of relevant studies. No language restrictions were set. The NCT number, study status, condition, and phase were noted for clinical trials. Results: There are only three gene and cell therapies for sarcomas that have been approved by a federal regulatory agency. Rexin-G: the first tumor-targeted gene therapy vector designed to target all advanced solid malignancies, including chemo-refractory osteosarcomas and soft tissue sarcomas, was approved by the Philippine FDA in 2007. Gendicine was the first oncolytic virus approved for intratumoral delivery in China in 2003. Afami-cel, an innovative chimeric antigen receptor (CAR) T cell therapy, was approved for synovial sarcoma in the United States in 2024. Other promising therapies are discussed in the text. Conclusions: The future of gene and cell therapy for sarcomas holds great promise, as research moves to late-stage clinical development. The integration of gene and cell therapies into standard sarcoma treatment protocols has the potential to significantly improve the quality of life and outcomes for patients with this rare and challenging group of cancers. Full article

The delivery of biomolecules to target cells has been a longstanding challenge in biotechnology. DNA viruses naturally evolved the ability to deliver genetic material to cells and modulate cellular processes. As such, they inherently possess requisite characteristics that have led to their extensive study, engineering, and development as biotechnological tools. Here, we overview the application of DNA viruses to biotechnology, with specific implications in basic research, health, biomanufacturing, and agriculture. For each application, we review how an increasing understanding of virology and technological methods to genetically manipulate DNA viruses has enabled advances in these fields. Additionally, we highlight the remaining challenges to unlocking the full biotechnological potential of DNA viral technologies. Finally, we discuss the importance of balancing continued technological progress with ethical and biosafety considerations. Full article

Due to the minimal survival benefits of existing therapies for pediatric diffuse midline glioma (DMG) patients, new therapeutic modalities are being investigated. Immunotherapies such as CAR-T cells and oncolytic viruses (OVs) are part of these efforts, as evidenced by the increasing number of clinical trials. αβ T cells engineered with a high-affinity γ9δ2 T-cell receptor (TEGs) are immune cells designed to target metabolic changes in malignant or virally infected cells via BTN2A1 and BTN3A. Because the expression of BTN2A1 and BTN3A can be altered in tumor and infected cells, combining TEGs and OVs could potentially enhance the anti-tumor response. We investigated this hypothesis in the following study. We demonstrate that TEGs can indeed target DMG, which expresses BTN2A1 and BTN3A at varying levels, and that OVs can further enhance the expression of BTN3A—but not BTN2A1—in DMG. Functionally, TEGs killed DMG cell cultures, and this killing was further increased after OV infection of the DMGs with either adenovirus Δ24-RGD or reovirus R124 under suboptimal conditions. However, this additive effect was lost when γ9δ2 TCR–ligand interaction was boosted by pamidronate. This study demonstrates the additive effect of combining OVs and Vγ9Vδ2 TCR-engineered immune cells under suboptimal conditions and supports a combination strategy to enhance the efficacy of both therapeutic modalities. Full article

Melanoma, an aggressive skin cancer, presents significant therapeutic challenges. Consequently, innovative treatment strategies beyond conventional chemotherapy, radiation, and surgery are actively explored. This review discusses the evolution of immunotherapy in advanced melanoma, highlighting PD-1/PD-L1 inhibitors, mRNA vaccines, Talimogene Laherparepvec (T-VEC), and tumor-infiltrating lymphocyte (TIL) therapies. PD-1/PD-L1 inhibitors such as pembrolizumab and nivolumab block immune checkpoints, promoting T-cell cytotoxic activity and improving overall survival in patients with advanced melanoma. T-VEC, a modified oncolytic herpes virus, promotes a systemic anti-tumor response while simultaneously lysing malignant cells. mRNA vaccines, such as Moderna’s mRNA-4157/V940, take advantage of malignant-cell-specific neoantigens to amplify the adaptive immune response while protecting healthy tissue. TIL therapy is a form of therapy involving ex vivo expansion and reinfusion of the patient’s tumor-specific lymphocytes and has been shown to provide durable tumor control. While these therapies have demonstrated promising clinical outcomes, challenges such as tumor resistance, high financial burden, and limited accessibility pose challenges to their widespread use. This review explores combination therapies such as PD-L1 inhibitors with mRNA vaccines, or TIL therapy, which aim to enhance treatment through synergistic approaches. Further research is required to optimize these combinations, address barriers preventing their use, and control adverse events. Full article

As the mechanisms underlying tumorigenesis become better understood, the dynamic roles of cellular components of the tumor microenvironment, and their cross-talk with tumor cells, have come to light as key drivers of disease progression and have emerged as important targets of new cancer therapies. In the field of oncolytic virus (OV) therapy, stromal cells have been considered as potential barriers to viral spread, thus limiting virus replication and therapeutic outcome. However, new evidence indicates that intratumoral fibroblasts could support virus replication. We have demonstrated in a rat model of stromal-rich intrahepatic cholangiocarcinoma (CCA) that vesicular stomatitis virus (VSV) can be localized within intratumoral hepatic stellate cells (HSCs), in addition to tumor cells, when the virus was applied via hepatic arterial infusion. Furthermore, VSV was shown to efficiently kill CCA cells and activated HSCs, and co-culture of CCA and HSCs increased viral titers. Interestingly, this effect is also observed when each cell type is cultured alone in a conditioned medium of the other cell type, indicating that secreted cell factors are at least partially responsible for this phenomenon. Partial reduction in sensitivity to type I interferons was observed in co-culture systems, providing a possible mechanism for the increased viral titers. Together, the results indicate that targeting activated HSCs with VSV could provide an additional mechanism of OV therapy, which, until now has not been considered. Furthermore, these findings suggest that VSV is a potentially powerful therapeutic agent for stromal-rich tumors, such as CCA and pancreatic cancer, both of which are very difficult to treat with conventional therapy and have a very poor prognosis. Full article

In this study, we present an oncolytic virus (OV) evaluation system established using microfluidic organ-on-a-chip (OOC) systems and patient-derived organoids (PDOs), which was used in the development of a novel oncolytic virus, AD4-GHPE. An OV offers advantages such as good targeting ability and minimal side effects, and it has achieved significant breakthroughs when combined with immunotherapy in recent clinical trials. The development of OVs has become an emerging research focus. PDOs can preserve the heterogeneity of in situ tumor tissues, whereas microfluidic OOC systems can automate and standardize various experimental procedures. These systems have been applied in cutting-edge drug screening and cell therapy experiments; however, their use in functionally complex oncolytic viruses remains to be explored. In this study, we constructed a novel recombinant oncolytic adenovirus, AD4-GHPE, and evaluated OOC systems and PDOs through various functional validations in hypopharyngeal and breast cancer organoids. The results confirmed that AD4-GHPE exhibits three antitumor mechanisms, namely, tumor-specific cytotoxicity, a reduction in programmed death ligand 1 (PD-L1) expression in tumor cells to increase CD8⁺ T-cell activity, and granulocyte–macrophage colony-stimulating factor (GM-CSF) secretion. The evaluation system combining OOC systems and PDOs was efficient and reliable, providing personalized OV treatment recommendations for patients and offering industrialized and standardized research ideas for the development of OVs. Full article

Ovarian cancer (OC) remains the most lethal gynecologic malignancy with limited effective treatment options. Oncolytic viruses (OVs) have emerged as a promising therapeutic approach for cancer treatment, capable of selectively infecting and lysing cancer cells while stimulating anti-tumor immune responses. Preclinical studies have demonstrated significant tumor regression and prolonged survival in OC models using various OVs, such as herpes simplex. Early-phase clinical trials have shown a favorable safety profile, though the impact on patient survival has been modest. Current research focuses on combining OVs with other treatments like immune checkpoint inhibitors to enhance their efficacy. We provide a comprehensive overview of the current understanding and future directions for utilizing OVs in the management of OC. Full article